topographic variation
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2021 ◽  
Vol 873 (1) ◽  
pp. 012049
Author(s):  
E J Wahyudi ◽  
A Laesanpura ◽  
D Sukmayadi

Abstract The study of field camp geophysics in Karangsambung has been done since 1996 until 2019 by geophysical engineering ITB. During the field activities, students was assigned with several data acquisition using various geophysical methods. One of the most common method to conducted alongside with surface geological mapping is gravity. Compilation of gravity data during the activities will be presented in this work. There are two categories of data compilation during 24 years: data compilation 1996-2004, and 2005-2019. The observation conducted using relative gravimeter with data distribution already cover geological surface map in the study area (Luk-Ulo Melange Complex, Karangsambung Formation, Totogan Formation, and Diabas Intrusion). The pattern of gravity observation shows correlated with topographic variation. Range gravity observation from this study is about 62 mGal.


2021 ◽  
Author(s):  
Nigel Roberts ◽  

<p>A fully probabilistic post processing system called IMPROVER has been developed at the UK Met Office. IMPROVER provides frequently updated probabilistic gridded forecasts, as well as forecasts for point locations, for input into automated forecast generation and for users such as operational meteorologists. Although the outputs are probabilistic, a deterministic interpretation can be extracted if required.</p><p>The scientific rationale behind this endeavor is the need to make more optimal use of the current and future generations of convection-allowing Numerical Weather Prediction (NWP) models and ensembles. The aim is to provide seamless, calibrated, probabilistic forecasts that are a blend of NWP models/ensembles from nowcasting to medium range. Today’s NWP systems offer not only many ensemble members but also frequent updates making it very difficult for users to manage the data and exploit latest information, so a key capability of IMPROVER is the frequent cycling, providing a continuously updated forecast blending the most recent available data.</p><p>Several key scientific benefits arise from the probabilistic approach on top of the capability to provide probabilistic outputs. Probabilities allow much simpler and effective blending with older forecasts or between different models/ensembles. We have introduced a variety of probabilistic neighbourhood methods to account for the inherent limited predictability at small scales. Some of these can incorporate topographic variation which is particularly important for variables such as rain, sleet and snow or fog. The ensemble-probabilistic approach has also enabled the use of ensemble calibration methods, which can not only improve skill and spread, but create a much more seamless transition between models/ensembles at different resolutions.</p><p>The system is built with a modular software framework that allows flexibility for future development and includes verification at every stage of the processing. IMPROVER is now routinely running with operational support and is expected to become fully operational in 2022. This presentation will briefly describe the initial scientific vision and current IMPROVER capability and discuss where any compromise or re-evaluation had to be made along the way. Finally, thoughts about the future and lessons learnt will be shared.</p>


2021 ◽  
Vol 314 ◽  
pp. 03004
Author(s):  
Zineb Moumen ◽  
Ismail Elhassnaoui ◽  
Fatima Daid

Hydrological data are mandatory for the elaboration of studies related to water management. Statistical analysis is a crucial step for the grasping of the distribution of data range. The presented study consists on applying statistical descriptive analysis on three climate variable; precipitation, temperature and relative humidity. Two gages stations were used; Bab Marzouka and Idriss First in Innaouène watershed. The obtained results underlines that the temporal variation exposes an overall rising trend in the temperature and a decreasing trend in the rainfall and relative humidity over the fours studied decades, it also uncovers the intra-seasonal fluctuation, humid and rainy in the winter and sec and dry in the summer, the autumn and the spring are considered as transition season where the temperature is moderated. The spatial variation is marked by a slight decreasing in precipitation and increasing of temperature moving from the middle part of the watershed to the downstream, which could be explained by the topographic variation and its impact on the climate. High altitude are generally marked by high precipitation and lower temperature comparing to lowlands areas.


Fire ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 13 ◽  
Author(s):  
Suyanti Winoto-Lewin ◽  
Jennifer Sanger ◽  
James Kirkpatrick

There are conflicting conclusions on how the flammability of wet eucalypt forests changes in the time after disturbances such as logging or wildfire. Some conclude that forests are most flammable in the decades following disturbance, while others conclude that disturbance has no effect on flammability. The comparative flammability of Eucalyptus nitens plantations in the same environment as wet eucalypt forest is not known. We determined fire incidence and fire severity in regrowth, mature and old growth wet eucalypt forest, and E. nitens plantation, in the Huon Valley, Tasmania after the January–February 2019 wildfire. To control for topographic variation and fire weather, we randomly selected sites within the fire footprint, then randomly located a paired site for each in different forest types in the same topographic environment within 3 km. Each pair of sites was burned on the same day. Old growth forest and plantations were the least likely to burn. Old growth and mature forest exhibited scorched eucalypt crowns to a much lesser degree than regrowth forests. In a comparison of paired sites, plantation forest was less likely to burn than combined mature and old growth forests, but in all cases of detected ignition the canopy of plantation was scorched. The lower flammability of older forests, and their importance as an increasing store of carbon, suggests that a cessation of logging outside plantations might have considerable benefits.


2020 ◽  
Vol 10 (7) ◽  
pp. 2518 ◽  
Author(s):  
Jiaying Li ◽  
Weidong Wang ◽  
Zheng Han ◽  
Yange Li ◽  
Guangqi Chen

Digital elevation models (DEMs) are fundamental data models used for susceptibility assessment of landslides. Due to landscape change and reshaping processes, a DEM can show obvious temporal variation and has a significant influence on assessment results. To explore the impact of DEM temporal variation on hazard susceptibility, the southern area of Sichuan province in China is selected as a study area. Multitemporal DEM data spanning over 17 years are collected and the topographic variation of the landscape in this area is investigated. Multitemporal susceptibility maps of landslides are subsequently generated using the widely accepted logistic regression model (LRM). A positive correlation between the topographic variation and landslide susceptibility that was supported by previous studies is quantitatively verified. The ratio of the number of landslides to the susceptibility level areas (RNA) in which the hazards occur is introduced. The RNA demonstrates a general decrease in the susceptibility level from 2000 to 2009, while the ratio of the decreased level is more than fifteen times greater than that of the ratio of the increased level. The impact of the multitemporal DEM on susceptibility mapping is demonstrated to be significant. As such, susceptibility assessments should use DEM data at the time of study.


Diversity ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 56 ◽  
Author(s):  
Raimo Virkkala ◽  
Juha Aalto ◽  
Risto K. Heikkinen ◽  
Ari Rajasärkkä ◽  
Saija Kuusela ◽  
...  

Increased attention is being paid to the ecological drivers and conservation measures which could mitigate climate change-induced pressures for species survival, potentially helping populations to remain in their present-day locations longer. One important buffering mechanism against climate change may be provided by the heterogeneity in topography and consequent local climate conditions. However, the buffering capacity of this topoclimate has so far been insufficiently studied based on empirical survey data across multiple sites and species. Here, we studied whether the fine-grained air temperature variation of protected areas (PAs) affects the population changes of declining northern forest bird species. Importantly to our study, in PAs harmful land use, such as logging, is not allowed, enabling the detection of the effects of temperature buffering, even at relatively moderate levels of topographic variation. Our survey data from 129 PAs located in the boreal zone in Finland show that the density of northern forest species was higher in topographically heterogeneous PAs than in topographically more homogeneous PAs. Moreover, local temperature variation had a significant effect on the density change of northern forest birds from 1981–1999 to 2000–2017, indicating that change in bird density was generally smaller in PAs with higher topographic variation. Thus, we found a clear buffering effect stemming from the local temperature variation of PAs in the population trends of northern forest birds.


2019 ◽  
Vol 9 (2) ◽  
Author(s):  
S.G. Srinivas ◽  
Y.L. Krishnamurthy

India is a subcontinent in the world with varied climatic regions, topographic variation results in the very diverse ecological diversity. Litsea is a largest genus in the family Lauraceae differentiated by its dioecious nature, distributed in tropical and subtropical regions which is influenced by some environmental factors. Present research work focussed on distribution of genus in the central Western Ghats of Karnataka, India. Litsea species were collected from 2013 to 2018 in different sampling sites.  A total of 12 species were identified and reported from this region. The diversity indices of Litsea vary from species to species as well as region to region. L. floribunda is frequently distributed in all the study sites and it showed highest density when compared with other species, whereas, L. deccanensis distributed only in Sakaleshpur region and it showed lower diversity. The highest number of Litsea species occurred in Sakaleshpur region (10 species) and Mullayyanagiri region having only one species that is L. floribunda. The results indicate that Litsea distribution and diversity is rich in moderate rainfall regions of Western Ghats. The macro and micro nutrients of the soil in the study area reflects the distribution of the genus. There is a gradual increasing in tendency of the species richness with increasing elevation when compared with lower elevated regions. The genus also showed more sensitive and positive association with the elevation factor.


2019 ◽  
Vol 100 ◽  
pp. 103467 ◽  
Author(s):  
Fernando Elias ◽  
Ben Hur Marimon Junior ◽  
Fagner Júnior Machado de Oliveira ◽  
José Carlos Antunes de Oliveira ◽  
Beatriz Schwantes Marimon

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